I’m sorry to hear you’re having a hard time. It can be difficult to reconcile something you consider part of yourself being shared by others alwhile they also do or say things that you know are wrong. Regardless of your particular doctrines views on the matter, on paper it’s not acceptable to wish harm on others or celebrate it.

I don’t believe in a deity, and I don’t hold it against anyone who does.

What you need to do, in my opinion, is taken a step back and ask yourself if you do or not, or if you’re just not sure.
Then think about what makes you say you don’t want to leave. You shared good reasons for wanting to leave, so what are your reasons for staying? What are you getting out of it?

Once you know where you stand on dieties, and have thought about what you’re reluctant to let go you’ll be in a better position to do what’s right for you.
Some people stay in a religion for social reasons.
You might be able to find what you need from the church elsewhere.

Regardless of the answers, remember that you can choose to live the highest ideals of Christianity regardless of membership in a church or faith in any diety. That affiliation with people who are failing at that has caused distress is at least a sign that you’re pointed in that direction, so trust in yourself and try to act with kindness and love, and look after yourself.